The AC compressor is not ON until the Electromagnet Clutch mechanism that mounts on the front of the compressor kicks in to engage the drive to the compressor, you manually activate this when you press AC ON in the cabin. If it is in fact the compressor that is making the racket & on assumption you don't drive with the AC on all the time then its most likely the Electro Magnet clutch that has stuck on leaving your AC Compression spinning all the time & eventually has snuffed the bearings in it. If this is the case you could get a cheap replacement from a breakers and install ensuring the electromagnet clutch is not stuck ON.
You cant cut the belt to the compressor as that belt ( if I am correct goes to the power steering and alternator also) mine is a 2.0 diesel and that is the way its setup. Without a VIN number I dont 100% know what way your is but if you look at the belt you will see what other dependencies there are on the belt.